1. Field of the Invention
This invention relates to drills and drill bits and in particular to the construction of drill bits with improved efficiency in the removal of discharging chips in the cutting of holes in a workpiece.
2. Discussion of the Prior Art
In the manufacture of drill bits for the cutting of holes in metals and woods, one of the problems encountered is the removal of chips which are obtained through the cutting process. In many cases the chips, which are being removed during drilling, can cause binding of the drill bit therefore requiring the drill to be shut off, and the drill bit removed from the hole. The hole then has to be cleaned out of the chips before the drill bit can be re-inserted and the drilling restarted. This stopping and restarting results in a very inefficient drilling or cutting process.
A number of prior art references teach a number of different types of drill bits which have been constructed to eliminate or at least improve the efficiency of the removal of chips during the drilling of holes in metals, woods and the like. For example, U.S. Pat. No. 2,769,355 teaches a fluted cutting tool which provides for the breaking up of the material drilled by the drill bit or cutting tool into small pieces to facilitate the clearing of the material from the flute. However, it has been found that the breaking up of the material into small chips during the cutting process is not desirable. It has been found that efficiency is improved and less down time is needed if the drill bit is constructed so that the chip coming out of the cutting process is not in small pieces but is in a long sustained curl.